Hurricane Categories: Missing The Big Picture?

We’ve become accustomed to hearing the one to five rating for hurricanes, but do you know what those categories mean? BPR’s Helen Chickering set out to find the answer and talked to a local hurricane researcher who thinks the rating scale is misleading.

The 1-5 categories used to describe the strength of a hurricane are based on of the Saffir-Simpson scale developed in the 1970s,

The scale separates hurricanes into five different categories based on sustained wind speeds. At the bottom category 1 storms have wind speeds starting at 74 mph. Category 5 storms have wind speeds starting at 157 mph.

“We’ve been telling folks for more than a decade that using the Saffir Simpson scale to characterize the potential impact from hurricanes like Irma is problematic,” says Young. “ It really doesn’t tell the whole story. The Saffir Simpson scale does tell you about the wind speed, but it doesn’t tell you really anything about the potential storm surge might be, doesn’t tell you anything about how much precipitation storm will drop, so it really doesn’t do a very good job on its own of characterizing the potential impact and whether storm going to catastrophic or not.”

From the air, Rob Young surveys the damage caused by Hurricane Katrina in 2005

“So, you have this combination of factors, size of the storm, shape of the coast, how shallow the water, all of these things really impact the storm surge, probably to a larger degree than the simple wind speed of the storm does, “says Young, “Hurricane Andrew which hit Florida in 1992, had incredibly strong winds, but it was a relatively tiny storm, so the storm surge not that big. On the other hand, hurricane Sandy was a monster storm and didn’t have terribly strong winds, but generated significant storm surge in New York and New Jersey. In some ways, the Saffir Simpson scale gets in the way of scientists adequately communicating the risk from any potential storm. “

Young says he’ll keep pushing for a more accurate hurricane impact rating system for the public. In the meantime, he recommends the National Hurricane Center’s website as a resource for storm watchers who want a more comprehensive hurricane picture.